Device for feeding steam boilers generating steam of high pressure



Nov. 7, 1933. H. HAHNLE 1,933,853

DEVICE FOR FEEDING STEAM BOILERS GENERATING STEAM OF HIGH PRESSURE Filed July 13, 1932 4 Sheets-Sheet 1 INVENTOR TTOIRA/EY NOV. 7, 1933. AH 1,933,853

DEVICE FOR FEEDING STEAM BOILERS GENERATING STEAM OF HIGH PRESSURE Filed July 13, 1932 4 Sheets-Sheet 2 INVENTUR ,4 TTOFP/VEY Nov. 7, 1933- HAHNLE 1,933,853

DEVICE FOR FEEDING STEAM BOILERS GENERATING STEAM OF HIGH PRESSURE Filed July 13, 1952 4 Sheets-Sheet 3 INVENTUR HERMANA/ HAW/m5 HTTORA/E Nov. 7, 1933. H. HKHNLE DEVICE FOR FEEDING STEAM BOILERS GENERATING STEAM OF HIGH PRESSURE I Filed July 13, 1932 4 sheets-sheet 4 57mm super/wafer INVENTU R A/E/FMAWA/ HAL /N45 Q T TOR/VEV Patented Nov. 7, 1933 DEVICE tron FEEDING STEAM B o I LE R s GENERATING SURE STEAM OF HIGH PRES- Hermann H'zthnle, Giengen-on-the-Brenz, Wurttemberg, Germany Application July 13, 1932, Serial No. 622,229, and in Germany November 3, 1926 7 Claims.

My invention relates to an improved feedingapparatus for steam-generators especially highpressure steam-generators.

An object of the invention is to provide a feeding-apparatus which enables the whole feeding of the steam-generator, according to its requirement during the work, without the use of a highpressure feed-pump exerting a sufficient pressure to overcome the pressure ofthe steam-generator.

Another object is to provide a feeding-apparatus by means of which a part of the generated high-pressure steam may be used for supplying the feed water to the generator and to provide, in combination with an apparatus of this character, means for recovering nearly the whole heat contained in the steam exhausting from the said feeding-apparatus subsequent to the removal of the feed water.

With the foregoing and other objects in view, the invention consists of certain novel combinations and arrangements of parts as may be best understood from the following description in connection with the appended claims and the accompanying drawings, in which- Figure 1 illustrates an embodiment of the invention having arranged in a feeding-pipe a heating-apparatus and, in series therewith, a'

feeding-apparatus;

Fig. 2 shows a modification which is of some importance in cases where the steam generator requires great quantities of feed water;

Fig. 3 is another modification wherein the feed:

water is heated by steps, and

Fig. 4 shows an arrangement illustrating the means I prefer to use for recovering the heat of superheated steam exhausting from the feedingapparatus.

Referring more particularly to Figural, 1 denotes a steam-generator which receives its feed water from an open reservoir 2. 5 is the feed pump. Arranged in series in the feed conduit are a heating apparatus 3 closedagainst the atmosphere and a receptacle 4 constituting the feeding-apparatus proper. The pressure pipe 6 of the pump 5 is connected to the bottom part of the heating apparatus 3 while a conduit 8 departing from the top of the heating apparatus and provided with a check valve '7 is connected to the bottom part of the feed apparatus 4. Disposed in the feed apparatus 4 is an insulating cylinder 9 spaced apart from the inner wall of the receptacle 4 and leading from the top nearly to the bottom of said receptacle. A pipe 11 departing from the bottom of the receptacle 4 and provided with a valve is) connected to the lower part of the boiler '1. A steam pipe 13 the receptacle 4 and of the cylinder 9 respectively while a pipe 15 provided with a valve 1-1;, is connected to a heating coil 16 arranged in the heating apparatus 3. The other end of said heating coil leads to a steam trap 1 from which the condensing water is supplied to the reservoir 2. The valves l0, l2 and 14 are controlled by means a fluid under pressure, for instance oil; which is sucked up from a reservoir 20 by the pumps 18 and 19. The oil ways are determined by distributing pistons 21 and 22 which are operated by floats 23. The floats 23 can slide along the piston bars 2 lwhich are provided with abutments 25 and 26 enabling the distributing pistons 21 and 22 to be moved up and down the weight of said pistons being balanced by springs 29. The valve bodies 30 of which that of the valve 12 is shown are rigidly connected to pistons 34 which may be displaced in cylinders 35 and are subjected to the influence of springs 3lby means of which the valves are commonly held closed. Connected to the cylinders 35 below the pistons 34 are oil'pipes 36, 36' of which the first designated is connected to the cylinder 27 and may becommunicated by means of the distributing piston 21 with the pressure pipe 37 of the oil pump 18 as well as with a branch line 39 of the discharging pipe 38. The oil pipe 36' is con nected to the cylinder 28 and may be communicated by means of the piston 22 with the pressure pipe 40 of the oil pump 19 or with the discharging pipe 41. V

In the position shown of thefioats 23, the distributing pistons2l and 22 are in low position. Owing to this, the pressure pipe 37 of the oil pump 18 is closed while the spaces below the pistons 34 of the valves 10 and .12 communicate through the pipes 36, the pipe 39 and the space above the piston 21 of the cylinder 27 with the discharging pipe 38. Consequently the oil below the pistons 34 of the valves 10 and 12 isremoved by the springs 31, and the valves 10 and 12are closed On the contrary, the way of the pressure oil through the cylinder 28 is held open bytthe piston 22, while the discharging pipe 41 is held closed. Thus, the piston 34 of the valve 14 is under the influence of the pressure-oil forwarded by the oil pump 19 and the valve 14- is held open. During the downward movement of the floats 23 the insulating cylinder 9 of the feed apparatus has been filled with steam as will be understood 11o from the explanations later on. This steam flows through the open valve 14 into the heating coil 16 of the heating apparatus 3 which is filled with water and rests under the pressure of the pump 5. This pressure is higher than the atmospheric pressure but essentially lower than the pressure of boiler 1. By means of the heating coil 16 the water in the heating apparatus 3 is highly heated so that the pressure of the steam contained in the cylinder 9 of the feed apparatus 4 sinks step by step. As soon as this pressure becomes so low that the pressure of the pump 5 is predominant the check valve 7 of the pipe 8 is opened. Owing to this, the hot water contained in the heating apparatus 3 is removed by the more cold water supplied by the pump from below so that the insulating cylinder 9 of the feed apparatus 4 is filled with this hot water. Thereby, the floats 23 rise and after having reached the abutments 26 of the piston bars 24 they shift the pistons 21 and 22. Consequently, the direction of the pressure oil is changed so that the valves 10 and 12 are opened while the valve 14 is closed. Then, steam flows from the boiler 1 into the cylinder 9 of the feed apparatus and the hot water contained in this cylinder is removed into the boiler whilst the check valve 7 is closed under the influence of the high pressure of the steam which enters the feed apparatus. The floats 23 returning into their lowermost position and finally pushing against the abutments 25 of the piston bars 24 cause the pistons 21 and 22 to be shifted again and the valves 10, 12 and 14 to be reversed so that the same operations will begin as hereinbefore described. In this way, the greatest amount of the heat contained in the steam exhausting from the feed apparatus is recovered in the hermetically closed heating apparatus 3. If, for instance, the generated steam has a pressure of 40 atm. and the pressure of the pump 5 is 2 atm., the feed water may be heated in the heating apparatus to a temperature of 115 degrees C. The insulating cylinder 9 serves to protect the walls of the feed apparatus 4 against the changes of temperature which are caused by the alternate filling of said apparatus with water and steam.

If it is desired, the heating apparatus may also be arranged in the feed line going from the feed apparatus to the boiler, whereby, advantageously, two alternately operated feed apparatuses are used in cases where the boiler requires great quantities of feed water.

An embodiment of this kind is shown in Figure 2.

To the bottom part of two feed apparatuses 4 and 4 of the same type as hereinbefore described are connected the branch pipes 6' and 6 respectively of a common feedpump 5' whereby check valves 7' and 7 are disposed in said branch pipes. Steam pipes 13' and 13 provided with valves 12' and 12 are connected to the boiler 1 with the one end and to the top of the feed apparatuses 4' and 4 respectively with the other end. Pipes 11 and 11" departing from the bottom partof the feed apparatuses and provided with valves 10 and 10 respectively are connected to a common heating apparatus 3 While pipes 15' and 15" departing from the top part of the feed apparatusesand provided with valves 14' and 14" respectively are connected to a common heating coil 16' arranged in the heating apparatus 3. The valves 10, 10", 12, 12", 14 and 14" are controlled by oil under pressure sucked I up by oil pumps 42 and 43 from a reservoir 44 and by oil pumps 45 and 46 from a reservoir 4'7.

The oil ways are determined by valves which are controlled, as described later on, partly by means of floats 23, 23" and partly by steam pressure, only one float being provided in connection with each of the feed apparatuses. Thus, the pressure pipe 48 of the oil pump 42 leads through a valve 49 which is held opened by the float 23 in its lowermost position to the cylinder 35 of the piston not shown of the valve 14 the arrange ment of said piston being the same as that of the piston 34 of the valve 12 in Fig. 1. A discharging pipe 50 leads from the said cylinder 35 to the oil reservoir 44 through a valve 51 which is held closed by the float 23 in its lowermost position. Besides this, the float 23 controls a valve 52 provided in the discharging pipe 53 of the cylinder '35 including the piston of the valve 10' the valve 52 being opened in the lowermost position of the float 23'. Connected to the said discharging pipe 53 is the discharging pipe 54 departing from the cylinder 35 of the valve 12. To the cylinders 35 of the valves 10 and 12 leads the pressure pipe 55 of the oil pump 45 through a valve 56, 57 which is shaped as a membranevalve like the membrane-valve 59, of the pressure pipe 58 of the oil pump 43 and the membrane of which be influenced by the pressure of the steam which fills temporarily the feed apparatus 4"} In the same manner, the said pressure pipe of the oil pump 43 leads through the membrane-valve 59, 60 to the cylinders 35 of the valves 10", 12" while the discharge pipes 61, 62 of the said cylinders are leading to the oil reservoir 47 through a valve 63 which is controlled by the float 23" closed in the upper pcsition'of the said float. The float 23" serves also to control the valves 64, 65 the valve 64 being provided in the pressure pipe 66 of the oil pump 46 connected to the cylinder 35 of the valve 14" and the valve 65 being provided in the discharging pipe 67 departing from the said cylinder.

If, as shown, the float 23' of the feed apparatus 4' is in its lowermost position the insulating cylinder 9' is fllledwith steam. Thereby the valves 49 and 52 are open while the valve 51 is closed. The pressure oil below the pistons of the valves 10 and 12 escapes through the pipes 53 and 54 so that the said valves are closed under the infiuence of springs (see valve 12 of Fig. 1). On the contrary, the pressure pipe 48 of the oil pump 42 which leads to the cylinder 35 of the valve 14' is open while the discharging pipe 50 is held closed by the valve 51.. The valve 14' thus'being open, steam flows from the feed apparatus 4 through the pipe 15' into the heating coil 16 of the heating apparatus 3. The water condensing in the said heating coil 16 is eliminated by a steam trap not shown. The heating apparatus 3" is filled with'the water which has previously been removed from the feed apparatus 4 and this water is now heated by the heat of the exhaust steam passing from the apparatus 4 through the heating coil 16'. Owing to this, the steam pressure in the apparatus 4 decreases and as soon as the temperature of the water contained in the heating apparatus 3 has been brought to a desired high the membrane-valve 59, 60 is opened the membrane 60 being under the influence of the steam of the apparatus 4 which communicates with said membrane through the pipe 68. The oil forwarded by the pump 43 flows through the pipe 58 and through the open or" the feed apparatus 4" and held 1.

valve 59 into the cylinders 35 of the valves 10"; v

This feed apparatus is filled with water so that the fioat 23" is in its uppermost position. Thereby the oil valves 63, 64 are closed while the oil valve 65 is open. Therefore the discharging pipes 61 and 62 departing from the cylinders 35 of the valves 10", 12" are closed and the valves 10", 12 are opened by the oil forwarded by the oil pump 43. Therefore steam from the boiler 1 flows into the heat apparatus 4" and the water contained in said .feed apparatus is removed through the pipe 11 into the heating apparatus 3 from which the hot water previously heated by the exhaust steam of the feed apparatus 4' is removed into the boiler 1. At the same time, the check valve 7' of the branch pipe 6 is opened and the feed apparatus 4' is filled with water by the pump 5. During this, the membrane-valve 56, 57 which, through the pipe 69, is held under the influence of the steam contained in the apparatus 4", is closed so that the oil forwarded by the oil pump 45 cannot pass to the cylinders 10', 12' and these valves remain closed. During the filling of the feed apparatus 4' with water the float 23 rises and entering into its uppermost position it closes the oil valves 49, 52 while the oil valve 51 of the discharging pipe is opened. The oil escapes from the oil room of the cylinder 35 of the valve 14 and this valve is closed.

On the contrary, the float 23 of the apparatus 4" entering into its lowermost position opens the oil valves 65, 64 while the oil valve is closed so that now the same operations take place with respect to the apparatus 4" as have previously been caused in the lowermost position of the float 23 with respect to the apparatus 4. If then, owing to the heating of the water in the heating apparatus 3, the pressure of the steam contained in the apparatus 4" is decreased below that of the pump 5 whereby the desired temperature of the feed water is obtained the membrane-valve 56, 57 is opened and the oil forwarded by the pump 45 through said valve opens the valves 10', 12' appertaining to the feed apparatus 4. The water contained in this apparatus is now removed into the heating apparatus 3 from which the hot water is removed into the boiler 1. In this way the apparatuses 4 and 4 are operated alternately during the working of the boiler 1.

The exhaust steam of the feed apparatus may also be used to heat the feed water step by step in a heating apparatus having two or several steps. An embodiment of this kind is shown in Fig. 3. In this figure the means for controlling the valves disposed in the steam pipes and in the water pipes are omitted, as the same means as hereinbefore described may be used for this purpose or other known means, for instance contactmanometers or the like.

Corresponding to Fig. 3, the hermetically closed feeding apparatus has two steps 3", 3" arranged in series in the pressure pipe 6" of a pump 5" the suction pipe 11" of which is connected to the bottom part of the feed apparatus 4. The suction pipe of the pump 5" is provided with a valve 10" while a check valve 7" is provided in the pressure pipe 6" between the said pump 5" and the first step of the heating apparatus. The top part of the feed apparatus may be communicated with the steam space of the boiler l by means of the steam pipe 13 provided with the valve 12". Another steam pipe 15" provided with a valve 14" leads from the top of the feed apparatus 4" to a heating coil 16" arranged in the second step 3" of the heating apparatus and connected with its other end to a steam trap not shown. A heating coil 16" arranged in the first step 3 of the heating apparatus is connected with one end by the pipe 15" to the top part of the feed apparatus'4 and with the other end to a steam trap not shown, a valve 14 being provided in the said pipe 15" Finally, a steam pipe 15" 'leads from the top part of the feed apparatus to a heating coil 16" arranged in a preheater which is provided in the pressure pipe 6" of the feed pump 5" Valves l4 and 7 from which the last designed is a check valve are provided in the pipes 15" and 6" respectively and a steam trap 17 is connected to the end of the heating coil 16" I The operation is as follows:

If the feed apparatus 4" is filled with water the valves 10" and 12" are opened while the other valves remain closed. The steam entering the feed apparatus removes the-water contained therein into the first step 3" of the heating apparatus while the hot water previously heated in this step is removed into the second step 3" from which the hot Water of highest temperature is removed into the boiler 1. The pump 5" serves to overcome thereby the friction resistances of the water pipes. The water being removed from the feed apparatus the valves 10" and 12" are closed while the valve 14" is opened for instance with the aid 'of a contact manometer. Therefore steam flows from the feed apparatus into the coil 16" ofthe second step of the heating apparatus. The water contained therein and previously heated in the first step 3" is then heated to the desired final temperature whereby the pressure of the steam contained in the feed apparatus decreases correspondingly.

At a given lower pressure the valve 14" is closed" and at the same time the valve 14" opens so that now steam flows from the feed apparatus into the heating coil 16" of the first step 3" of the heating apparatus. This step being filled with water which has been preheated in the preheater '70 this water is now heated to a middle temperature, the pressure of the steam contained in the feed apparatus decreasing further. As soon as the desired temperature of this water. is attained the valve 14" is closed while at the same time the valve 14" is opened so that the rest of the exhaust steam of the feed apparatus flows into the heating coil 16" of the preheater 70. At the same time the valve 7" is opened so that the apparatus 4" is again filled with water by the pump 5" and the whole rest ofthe exhaust steam is removed from the feed apparatus into the heating coil of the preheater 70. After the feed apparatus being filled again,

the valves 14 and 7" are closed and the valves 10" and12" are opened so that the same operations take place as here'inbefore described. 1

If, f or instance, the feed apparatus is filled with steam of about 150 atm., 340 degrees C. it contains 95 kg. steam with a heat content of nearly 613 calories/kg. The pressure within the feed apparatus may fall, during the heating of the water within the second step of the heating apparatus, to 100 atm. In the heating coil 16" are thereby obtained 40 kg. condensing water of 100 atm. with a heat content of 330 calories/kg. This condensing water may be used as feed water. In the feed apparatus remain 55 kg. steam of 100 atm., 340 degrees C. and with a heat content of 640 calories/kg. and this steam may be step 3" of the heating apparatus has a temperature of 200 degrees C. it may be brought within this step to a middle temperature of 215 degrees C. In the second. step the temperature is then raised to 290 degrees C.

If the water entering into the step 3? has a temperature lower than 200, degrees C. the steam pressure may be decreased within this step below 30 atm. The pressure of the pump 5 is then correspondingly lower.

In cases where the steam generated within the boiler 1 is superheated, its heat contents may partly be used-for generating saturated steam within the boiler itself. g This is illustrated in Fig. 4 which shows the same embodiment as Fig. 3 but a cooling coil 71 being arranged within the boiler 1 between the heating coil 16" and the feed apparatus. By this cooling coil a part of the heat contents of the steam exhausting from the feed apparatus is supplied to the water within the boiler 1 and used for generating saturated steam before the steam is entering into the heating apparatus.

If it is desired, the superheated steam exhausting from the feed apparatus may also be used to drive a steam engine before it is supplied to the heating apparatus. Also, the exhaust steam may be supplied to a steam accumulator intercaled between the feed apparatus and the heating apparatus. In this way a continually heating of the water within the heating apparatus may be obtained.

What I claim is:

1. An improved device for feeding boilers gen erating steam. of high pressure, comprising in combination with the boiler, a feed pump working with a pressure higher than atmospheric pressure but essentially lower than the boiler pressure, a feed apparatus and a hermetically closed heating apparatus intercalated in series in the feed conduit, a steam pipe connecting the top part of the feed apparatus with the steam space of the boiler, a steam. pipe connecting the top part of the feed apparatus with a heating coil within the heating apparatus, and automatically controlled valves in the feed conduit and the said steam pipes said valves enabling the feed apparatus to be alternately filled with water and with steam and being arranged to communicate the lower part of the feed apparatus with the Water space of the boiler during the entrance of the steam and to communicate the top part of the feed apparatus with the heat apparatus after the water has been removed by the entering steam and to communicate finally the lower part of the feed apparatus with the feed pump after the steam pressure within said apparatus has decreased to the desired extent.

2. A feeding device as claimed in claim" 1, the

feed apparatus being provided with an insulating cylinder open at the-bottomand extending from the top of said feed apparatus nearly to its bottom said cylinder being spaced apart from the side walls of the feed apparatus and adapted to protect said side walls against the changes of temperature occurring within the feed apparatus during the change of its contents.

3. A feeding device as claimed in claim 1, the feed apparatus being shaped as two step appara' tus and the heating coils of the two steps being enabled by automatically controlled valves to communicate the one after the other with the steam space of the feed apparatus corresponding to the decrease of the steam pressure within said feed apparatus, a preheater being disposed in the feed pipe between the feed pump and the feed apparatus, the heating coil of said preheater being enabled by an automatically controlled valve to receive the rest of the-exhaust steam of the feed apparatus after the steampressure within said apparatus has decreased to the desired extent.

4. A feeding device as claimed in claim 1 comprising, in combination with a boiler generating superheated steam, a steam. cooler being arranged within the boiler between the feed apparatus and the heating apparatus and in series with the heating coil of the heating apparatus.

5. A feeding device as claimed in claim 1 comprising, a second feed apparatus being arranged in parallel with a first feed apparatus, said second apparatus being enabled by automatically controlled valves to be operated alternatelywith said first apparatus and the feed pump and the heating apparatusbeing adapted by automatically controlled valves to cooperate alternatelywith each of said two feed apparatuses.

6. A feeding device for boilers, comprising in combination with a boiler, a feed apparatus having side walls and an insulating cylinder-spaced apart from said side walls; a heating apparatus connected in series with said feed apparatus and having a heating coil; a steam pipe connecting said feed apparatus with the steam space of said boilenanother steam pipe connecting saidfeed apparatus with saidheating coil, a second feed apparatus connected in parallel with the firstmentioned feed apparatus, and means for alternately operating the same.

'7. A feeding device for boilers, comprising in combination with a boiler, a feedapparatus, a heating apparatus connected in series with said feed apparatus, and-having a heating coil;. a steam-pipe connecting said feed apparatus with the steam space of said boiler, another steam pipeconnecting said feed apparatus with said heating coil, and a steam cooler situated within the boiler between said feed apparatus and said heating apparatus and connected in series with said heating c0il.

HERMANN HAHNLE: I 

